1. Field of the Invention
The present invention relates generally to an illumination apparatus, and more particularly, to an illumination apparatus using a light guide and a portable terminal having the same.
2. Description of the Related Art
An illumination apparatus with a light guide is generally used as the backlight for a Liquid Crystal Displays (LCDs), or to illuminate portable terminal keypads. Such an illumination apparatus conventionally includes a light guide having the shape of a rectangular flat board and guiding light through multiple reflections between its upper and lower surfaces. The light guide includes light extraction patterns provided to output the light within the light guide to the exterior at the upper and lower surfaces.
U.S. published application No. 20060260922, published on 23 Nov. 2006 and entitled “Keypad and Keypad Assembly”, discloses a light guide panel for keypad illumination. The light guide panel illuminates a plurality of key buttons on the keypad by reflecting the light towards the panel exterior. The light is generated by luminous elements and is input into the guide. The panel includes a plurality of reflection patterns that are locally formed on the key buttons on a one-to-one basis, to reflect a part of the light propagating in the light guide panel toward the associated key buttons for each pattern.
Since most consumers consider the design of manufactured goods in purchasing portable terminals, attempts are being made to improve external illumination of the products.
The illumination apparatus with a light guide is attractive due to its efficient use of resources and high illumination uniformity. However, when used for external illumination of portable terminals, the conventional illumination apparatus with a light guide has low resource efficiency and difficult implementation, as well as inefficient light-output.
Accordingly, there is a need in the art for an illumination apparatus with a light guide, which can be efficiently applied for external illumination of portable terminals.